Calcium polycarbophil-alginate controlled release composition and method

A method of controlled release treatment comprising the steps of:

• (a) providing a polymeric complex and an active agent selected from the group consisting of medicinal agents and cosmetic agents contained within said complex, said polymeric complex comprising a reaction complex formed by the reaction of (1) 0.1% to about 90% calcium polycarbophil which is a water-swellable, but water-insoluble, fibrous, cross-linked carboxy-functional polymer, said polymer containing (a) a plurality of repeating units of which at least about 80 percent contain at least one carboxyl functionality, and (b) about 0.05 to about 1.5 percent cross linking agent substantially free from polyalkenyl polyether, said percentages being based upon the weights of the unpolymerized repeating unit and cross-linking agent, respectively, or a salt thereof, with (2) from about 0.1 to about 99.9 percent of alginic acid or a salt thereof, said interaction being performed in the presence of said active agent, said interaction being at a pH from about 3 to about 10, and the calcium polycarbophil being originally present, prior to said interaction, in the form of the calcium salt, having a calcium content of from about 5 to about 25 percent, based on the weight of the polycarbophil, and wherein the ratio of said reaction complex to said active agent is about 200,000:1 to 1:100';
• and
• (b) contacting an area of skin or mucous membrane to be treated with said composition for a period of time to allow a therapeutically effective amount of said active agent to be released from the complex.